Variable-speed transmission.



H. HUEBER. I

VARIABLE SPEED TRANSMISSION.

APPLICATION FILED MAR 6| 1914- RENEWED FEB 20.1918.

1,279,547. Patented Sept. 24, 1918'.

TED STATES PATENT OFFICE.

HENRY HUEBER, OF SEATTLE, WASHINGTON.

VARIABLE-SPEED TRANSMISSION.

Specification of Letters Patent.

Patented Sept. 24, 1918.

Application filed March 6, 1914, Serial No. 823,030. Renewed-"February 20, 1918. Serial No. 218,356.

To all whom it may concern Be it known that I, HENRY HUEBER, a citizen of Germany, and resident of the city of Seattle, in the county of King and State of Washington, have invented certain new and useful. Improvements in a Variable- Speed Transmission, of which the following is a full, clear, and exact description. I

The object of my invention is to supply a variable speed transmission which will automatically run from high to low gear or vice versa, through the medium of expanding or contracting disk pulleys and the further object is to reduce to a minimum the loss of power in the transmission thereof.

This expansion. or contraction to be automatically effected by the varying tensions of the transmission belt, said variations being directly due to natural causes independ-- ently ofany mechanical action on the part of the operator. a

It may be observed that the virtue of this invention resides in the automatically varying transmission, which responds to the different road conditions to which the car may be subjected.

It is evident that any sudden or gradual added strain or relaxation which may be placed upon the transmission belt by any external causes will be immediately transmitted to the contracting and expanding friction disks which comprise the pulley action. I I This invention is particularly applicable to cycle cars, or light automobiles, lathes and drill presses or any other form of machinery in which an automatic variable speed is desirable. 7

Having thus indicated the ends sought by me my invention consists in the construe: tion and combination of parts to be more fully described hereafter and particularly set forth in the claims. Reference is to be had to the accompanying drawings forming a part of this specification in which similar characters of reference indicate corresponding parts in all the figures.

In the drawings:

Figure 1 illustrates the side view of a cycle car to which my device is particularly applicable.

Fig. 2 is a plan View of the device in part section showing the expansible pulleys in high gear.

Fig. 3, is a sectional view of the pulley action showing the application thereof in which is mounted upon the frame Y of the car. The driving shaft 1, is adapted to be mounted within bearings 2, said bearings being adjusted to the frame. Y of the machine. Upon this driving shaft 1, Fig. 2

, is provided an expansible pulley 3, consisting of two independent cone disks A and B. Disk A is adapted to be rigidly adjusted'to the shaft 1 by a key 4, whereas, disk B is adapted to be rotatably mounted upon the shaft 1 and longitudinally actuated by ill:

screw gearthereof.

It is to be understood that these cone disks can be provided with sleeves to give greater purchase rigidity. thereto. A coil spring 5 is interposed between the nut 6 and cone disk B to assist contraction thereof. However,

in actual operation it has been found unessential. A V-shaped belt 7 Figs. 2 and 3 is adapted to engage said pulleys and transmit power to a similar pulley on the counter shaft 8. Disk G thereof is rigidly adjusted to a sleeve 9 which is slidably mounted upon said counter shaft. 1

Any diflerence in the tension of this transmission belt, due to any cause whatever, au-

tomatically adjusts the gear ratio between the two friction disk pulleys in the following manner: I

In Fig. 2 the transmission belt is shown as operating at high speed and running at the peripheral edges of the driving disks A and B and near the axes of the counte'rshaft disks C and D. It can be observed that'a'ny 7 added tension, or tractive power placed upon the transmission belt, will act upon the rota 'tably mounted disk B in the nature of a thrust. This rotatably mounted disk is thereby caused torot'ate upon the screw upon which it is mounted in direct proportion to the amount of tension exercised by the transmission belt.

It has been found that when any increased tension is applied to the transmissionbelt 7 a creeping away of the disk B with respect 7 of the disk B causes disk B to increase its rotation with respect to disk A. and hence is moved away therefrom by the helical screw. As soon as the tension of the belt decreases below the said predetermined point of pressure, then the greater friction of the disk B with respect toits threads causes a lagging of its rotation upon the screw and hence moves toward the disk A thereby expanding the radius of the pulley.

To neutralize what would otherwise be a slackness in the belt from the expansion of the disk B on the driving shaft, the pulley on the counter shaft 8 is provided with a movable disk C which is actuated by the springs. 12 adapted to contract the disk through the medium of two bolts provided respectively with nuts 11. These bolts are rigidly adjusted to the disk 0 and slidably mounted through the rigid disk D. It is apparent that this spring contraction on the counter shaft pulley will automatically readjust any slackness in the belt and maintain a uniform tension in the transmission belt upon the pulley on the counter shaft.

In Fig. 5 is shown a variation of this action in that the screw principle employed on the driving pulley is likewise applied to the counter shaft pulley. In this when the ten' sion on the belt {7 is increased the crowding of the belt will cause a creeping of the disk B with respect to the disk A, the disk B having a rotary motion with respect to the disk A and being moved away therefrom by the helical screw, while the same increased tension will cause the disk C to creep with respect to the disk D and be moved toward the disk D on the helical screw, the movable disks B and C being on opposite sides of their respective pulleys. The same result may be obtained by placing the movable disks ion the same side of their pulleys and using right and left hand screws respectively. It is preferable however, that the counter shaft pulley be provided with means by which the operator may control the gear ratio at will.

Thus in Fig. 3. is illustrated a lever operating mechanism comprised of a foot pedal.

10 slidably mounted upon the sleeve 9 of the disk C. Said lever provided with a helical transmitted through the hearings to the slidable friction disk C, thus giving the operator, at will, any desired gear ratio.

Upon the counter shaft 8 is provided a clutch 13 of well known construction mounted in the usual way and actuated by lever 14.

The gear ratio of the transmission is automatically adjusted regardless of road condi tions or clutch manipulations. y

In Fig. 2 is shown the driving pulley 30 connected with the counter shaft and directly applying the power to rear axle through the belt 16 by the engine drive 31.

The illustration 4 shows the mechanical action of the lever mechanismwvhich opcrates as follows: Pressure upon the serrated pedal 18 forces the ratchet 21 to desired point where it meshes with arm support 22. Ratchet is held. in position by spring 23. A similar spring 25 is mounted around stabilizing rod 24; This action forces the lever back in position when ratchet is released from the stationary rod or arm support 22.

Having thus indicated the ends sought by me, it is to be understood that while I have employed the gear principle to expand or contract the pulley disk which constitutes the essence of the variable speed transmission, such well known equivalents as a key way or a square shaft with ball races running on'fianges and controlled by a lever can be employed to expand or contract the above pulley action as they perform the same. function in substantially the same way and produce the same result.

What I claim as new and desire to protect by Letters Patent is 1. The combination with a rotatable shaft having a worm provided thereon, of an expansible pulley consisting of two independent cone disks, one of said disks adapted to be rigidly attached to the shaft, the other disk adapted to be rotatably mounted on said shaft and movable helically on said worm, a belt for moving away said helically mounted disk from said fixedly mounted lie disk, said helically mounted disk adapted to worm thereof, a belt for automatically moving said helically mounted disk to contract said pulley in response to an increase in tension of said belt, said pulley being adapted to be automatically expanded by said worm in response to a decrease of tension on said belt. I

3. A variable speed power transmission comprising a driving and a driven shaft, :1.

worm provided on said driving shaft, a cone shaped disk secured to said driving shaft a similar cone-shaped disk helically movable on said Worm longitudinally of said driving shaft whereby it may be moved toward or away from said first named disk, a cone shaped disk secured to said driven shaft, a similar cone shaped disk movable longitudinally on said driven shaft, elastic devices securing said last named disk to said first named disk on said driven shaft and a belt connecting said disks on said driven shaft With said disks on said drivingsha'fts.

4. A variable speed power transmission comprising a driving and a driven shaft, a Worm provided on said drlvmg shaft, a cone shaped disk secured to said driving shaft, an

opposed cone shaped disk helically movable on said Worm lengthwlse of said driving HENRY HUEBER.

Witnesses:

- PHILIP D. MAGBRIDE,

FRANK. W. BISHOP. 

